


pro bono

by sarcasticfluentry



Series: The Boundless Saga [1]
Category: Shadowhunters (TV)
Genre: Anal Fingering, Anal Sex, First Time, Kissing, Lots of kissing, M/M, Overstimulation, Plot What Plot/Porn Without Plot, Powerbottom Magnus, sort of? Alec is v overwhelmed
Language: English
Status: Completed
Published: 2016-03-24
Updated: 2016-03-24
Packaged: 2018-05-28 20:48:05
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 7,195
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6344575
Author URL: https://archiveofourown.org/users/sarcasticfluentry/pseuds/sarcasticfluentry
Summary: <blockquote class="userstuff">
              <p>After the Clave drops the charges against Isabelle and declares her free, Magnus decides he doesn't want Alec's bow and quiver after all. He gets something even better.</p>
            </blockquote>





	pro bono

**Author's Note:**

  * Translation into Polski available: [pro bono](https://archiveofourown.org/works/6802204) by [Martynax](https://archiveofourown.org/users/Martynax/pseuds/Martynax)



> So I'm malec trash now, I guess? Add this to my growing list of fandoms. Sorry for neglecting my WIPs? Here's 7k of porn as an apology?
> 
> I wrote this in 24 hours, basically..... love to [lila](http://tequilila.tumblr.com) for looking over it for me........ the title comes from the show itself.... y'all should watch Shadowhunters and scream about it with me on [tumblr](http://povverbottoms.tumblr.com).... oh and don't send this to any of the actors please. Respect my privacy and theirs. Thanks! Enjoy!

“Keep it safe for me, will you?”

And with that, Magnus turns to go. His heart feels heavy in his chest even though he supposes he should be happy – he’s grown to care for Isabelle, and he’d thanked the gods when she was let off the hook – but the Clave has the Cup and Alec’s still getting _fucking_ married to his flawless, dispassionate, and (presumably) dick-lacking fiancée.

Magnus has only taken a couple of steps, though, when something clatters to the ground behind him.

He whirls around, hands up defensively, and almost startles when he comes face-to-face (or, face-to-collarbone, really. It’s not a big deal. Magnus is fine.) with Alec.

“Magnus,” Alec says quietly, his voice just shy of cracking.

Magnus glances around Alec’s broad shoulder and sees his bow and quiver lying on the ground, arrows scattered everywhere. He clears his throat and asks, “Is something wrong?”

“Yes,” says Alec. “Ev – everything’s all wrong, and I don’t, um… is there somewhere we could talk?”

Magnus raises an eyebrow. That was _not_ what he was expecting.

Before he can answer, they both shift slightly apart as two students walk by them down the hallway.

“What, the middle of your parents’ institute isn’t private enough for you?” Magnus smirks.

Alec’s mouth twitches. It’s not a smile, but it’s close. “Not exactly…”

“Well you’re in luck, Alexander, because I have an apartment that I _love_ to use for talking,” says Magnus. “And… _other_ things, of course.”

Alec’s eyes flick to his mouth and he blushes slightly, pink staining his pale cheeks. Magnus wants him so much it’s manifesting in a physical ache.

“Well, maybe we could… um,” Alec scratches the back of his neck, “I don’t have anything planned right now, so I don’t think anyone would miss me…”

“Oh, I’m _sure_ someone will miss you, but it will be their burden to bear, not yours,” Magnus says, hoping his smile doesn’t look as bitter as he feels.

With a few waves of his hands and several seconds of intense concentration, a portal to his apartment appears next to them in the hallway. Alec makes a small noise in his throat, moves to step through it, and then stops. “My bow…”

“Is the least of our worries,” Magnus says quickly, snapping his fingers and willing the bow and quiver to return to their rightful place in the weapons cache. “Are you coming?”

With that, Magnus steps through the portal to his apartment. A tiny flicker of doubt stabs through him as he wonders if Alec will follow. God, no one’s quite teased out his insecurities like this in almost one hundred years.

Moments later, though, Alec joins him in his apartment and Magnus is able to relax a fraction – until he takes one look at Alec’s face and realizes that the younger man is already losing his nerve. Magnus snaps into action.

“Drinks?” He claps his hands once. “Drinks, yes.”

He walks over to his miniature bar and begins making them both cosmopolitans rimmed with glittered citrus sugar. He hears Alec take a couple of tentative steps into the room behind him.

Magnus reminds himself that it’s very likely Alexander hasn’t even had his first _kiss_ yet, so he’s probably never going to be confident enough to initiate anything, much less a conversation about their relationship, such as it is. It’s up to Magnus.

“You know,” he starts, turning around with a drink in each hand, “I wasn’t sure if you were going to hurt me or kiss me when you snuck up on me like that.”

Alec swallows loudly as Magnus hands him a drink. “To be honest, I… I wasn’t sure either. I just, like, I didn’t want you to leave, but I didn’t know how to make you stay.”

“Darling, all you had to do was ask,” Magnus purrs, settling delicately onto the arm of one of his gold couches. “Can I inquire as to what caused the change of heart without scaring you off?”

“You wouldn’t – okay, well – yeah, I’ve been kind of a dick,” Alec admits, taking a large sip of his drink and grimacing just like he did the last time Magnus made him something.

Magnus wants to ask if it’s the taste of alcohol that bothers him or the flavor of the drink, wants to offer to make him something else, but he doesn’t want to interrupt the speech that Alec seems to be preparing himself for.

“But that’s only because – I swear I’m not usually like this, Magnus, ever since Clary showed up Jace has been running around after her like some kind of lovesick tornado and _I_ get to be the bad guy for cleaning up their messes.”

“Which translates into you getting married… how, exactly?”

Alec sighs and sits down on the couch next to him. “Now, I have no clue. Originally it was because… my parents were gonna lose the Institute and I felt guilty for that being _my_ fault, somehow, even though it was mostly Jace’s fault, but _he_ wasn’t going to step up and do anything about it. And I didn’t _mind_ Lydia, right, she and I got along pretty well after we started talking, and I knew my parents were trying to figure out a marriage for me anyway-“ Here he pauses to take another large sip of his cosmo- “But after Lydia told them they were going to lose the Institute I knew that any attempt by _them_ to arrange a marriage would come off as, like, _too_ desperate.”

“So you decided to arrange your own marriage to shoot for an average amount of desperation?” Magnus asks.

“That was when I thought that there was something to _save,_ though,” Alec frowns. “I’ve been raised my whole life to see things in black and white, right and wrong, you know? And then I find out my parents used to be in the Circle and they never bothered to share _that_ little piece of information, and my own fiancée was going to prosecute my sister for treason even though she didn’t think it was the right thing to do, and that nobody else seemed to give a single _shit_ about fixing anything, they just wanted to take our problems and sweep them under the rug or banish them.”

“Except you,” says Magnus softly.

“Yeah, except me,” Alec snorts. “And look where that got me, I look like a fucking idiot and I’m all set to go into a loveless marriage with someone I’m not even attracted to, like, one bit. I’m just-“ He drains the rest of his drink- “I’m tired of doing things for, like, the common good. Mostly because I don’t even know what that is anymore. I just… I want to be selfish for once.”

Magnus is speechless.

“Do you have any more of this?” Alec asks, waving his glass around.

“Of course I do,” says Magnus, plucking the glass from his fingers and getting up off the couch. “But I’m not making it as strong this time. Getting you drunk would be… counterproductive, Alexander, would it not?”

“I’ve never even _been_ drunk,” Alec complains, following after him and watching him make the drink. Magnus’ little innuendo went right over his head. “I’ve never… done a lot of things. Sorry, I know I’m – there’s just so many things I haven’t experienced, just because I’ve been trying to do right by rules and people that don’t give a shit if I’m happy or not.”

“At the risk of sounding condescending, I’m glad you’ve finally realized that,” Magnus says quietly.

“I know,” says Alec. “I know you tried to – tell me, before. I’m sorry.”

Magnus smiles as he strains the cosmopolitan into Alec’s glass. “You don’t have to apologize.”

“But I want to,” Alec insists. He takes a sip of the cosmo and doesn’t wince at all this time. Magnus’ smile widens. “Because we could’ve – but it doesn’t matter, because now I’m getting married and I don’t really have anyone to blame but myself.”

“No one’s forcing you to get married,” Magnus points out.

Alec sighs. “Yeah, but – I can’t call it off now, can I? Even if I… want other things.”

His lips are wet from vodka and cranberry juice, stained redder than usual. Magnus has a good idea of what other _things_ he’s talking about.

“You can _always_ call it off,” he says, stroking a finger down Alec’s chest over the thin black material.

Alec’s eyes follow his hand. “I really… can’t…”

Their eyes meet, then, and Magnus knows. He knows that, as much as Alec wants to do the honorable thing, the wedding is not going to happen. He wouldn’t have done what he does next, otherwise.

The room feels almost unnaturally quiet as Magnus sets his glass down on the bar, then plucks Alec’s out of his hand and does the same.

“Magnus?” Alec asks, doe eyes wide as he licks his lips. Oh, this is going to be _fun._

He walks fingertips up over Alec’s shoulder, curls a hand around his neck before standing up on his tiptoes. Alec makes a small noise in his throat and brings one of his hands up to ghost over Magnus’ cheek.

Their first kiss – Alec’s first kiss _ever –_ is incredibly intense, magnetic to the point where after only a few seconds their bodies are pressed flush together as Alec’s lips slide over his. Alec is gentle, questioning, practically _begging_ for Magnus to take the lead, and so he does.

Alec moans at the first press of Magnus’ tongue against the seam of his lips. Magnus nearly overbalances, still standing on his tiptoes, when he tries to press forward and get impossibly closer, but he rights himself and licks gently inside Alec’s lush mouth. He finds Alec’s tongue, hot and soft and tentative, and teases it with his own, heat rolling through his body when Alec cups his face with both hands.

Magnus groans as Alec tugs him closer, jostling against the bar as Magnus bites gently on his lower lip. Alec _really_ likes that, makes this little _nnh_ sound that makes Magnus wish he wasn’t wearing very constricting dress pants.

When one of Alec’s hands slides over to the small of his back, Magnus sucks lightly on his tongue before pulling away, greedy with pleasure at how Alec tries to follow. “Couch?”

Alec blinks his eyes open. _Gods,_ he already looks fucked-stupid and Magnus has barely even _done_ anything. “What?”

“Should we take this to the couch?” Magnus elaborates, speaking slowly. “Your neck will hurt less.”

Alec blinks again, still staring at Magnus’ mouth. “My neck… my neck doesn’t hurt.

Magnus laughs. “Oh, it doesn’t hurt yet. But I don’t plan on stopping this for quite a while, Alexander.”

He barely even gets Alec’s full name out before Alec’s lips are back on his, eager. Magnus tugs on his waist a little bit and they stumble over to the couch that way, unable to let go of each other even for a few seconds. Alec keeps making these tiny little noises and Magnus wants to drink up each and every one of them.

When they finally get to the couch, Magnus backs Alec up against it and gives his chest a small push. Alec falls back onto the couch and looks up at him desperately – his pupils are blown wide, lips a little puffier than usual. Magnus spares a single second to light a fire in the fireplace across from the couch before sliding into Alec’s lap and picking back up where they left off.

The angle is much better like this; Magnus can wrap both of his hands around Alec’s neck without straining his calves, and Alec’s hands can truly wander all over him now, which he’s definitely taking advantage of. Alec’s touching him like he has to learn his entire body, like he’s going to be tested on it later, and Magnus arches into his hands, groaning against his lips when Alec tentatively pushes his tongue into his mouth.

Magnus tugs lightly on his hair just to see what kind of reaction he gets and Alec fucking _whimpers,_ his hips jolting up sharply in surprise. Before Magnus can process this and let all his blood go south, Alec pulls back, blushing furiously and biting his lip.

“What’s wrong?” Magnus asks quickly. “Did I hurt you?”

 _“No,_ no, I – sorry,” Alec stammers. His voice has gotten deeper. “I think I – liked it _too_ much.”

Magnus lets out a soft laugh of disbelief. “There is no such thing as liking something _too much,_ Alexander.”

He leans down and noses against Alec’s neck, relishing in how soft his skin is before laving over his pulse point with his tongue. Alec gasps quietly and Magnus takes that as permission to nip over the same spot with his teeth, scraping very gently before sealing his lips against Alec’s throat and sucking what he hopes will be a bruise.

 _“Ohh,”_ Alec groans, fingers tightening on Magnus’ waist.

Fuck, Magnus wants to _ruin_ him. Gently.

He wonders if Alec is as hard as he is, wonders if it would be too forward to check with his hips. Alec answers that question by jerking up against him when Magnus sucks with more force and it startles a moan out of him to feel just how affected Alec is by this. Fuck, Magnus wants that inside him _yesterday_.

“What the fuck,” Alec stammers, hands kneading at Magnus’ waist. “I didn’t – I didn’t know anything was, _oh,_ could feel this good.”

Magnus pulls back, finally, surveying his handiwork with a pleased smile. If he was feeling very mean he would cast a spell on the bruise to make it fade much slower than usual, but he has more pressing matters to attend to. “Don’t tell me you’ve never pleasured yourself.”

“No, I – I have,” Alec says, averting his eyes and blushing. Magnus clearly didn’t think this through, because now even the _thought_ of Alec getting himself off is making it difficult to think of anything else. “But it doesn’t – it’s not the same, you’re right _here-“_

Magnus cuts him off with another kiss, unable to spend another second apart from him. He rolls his hips forward now that they’ve cleared that point in the conversation, climbs a little bit closer then does it again. Alec groans raggedly against him, getting bolder with his tongue and especially his lips. He sucks on Magnus’ lower lip just like Magnus had done to him earlier – Magnus gets nearly dizzy with arousal when he realizes that Alec is trying to emulate things he does, that he could teach him _so much._

They’re rocking together now, small movements but firm enough that his poor dress pants are going to need a thorough magical cleaning. The fire is crackling behind them, making the whole room smell pleasantly smoky, and between that and whatever cologne Alec’s wearing, Magnus is about ready to throw him down on the carpet and have his way with him.

“How far do you want to take this, sweetheart?” he asks, pulling back so he can give Alec time to answer. The dark bruise on his neck looks _sinful_ against his pale skin.

Alec swallows. “Whatever you want to do is fine.”

Magnus chuckles. “Oh, but I want to do _so_ many things, Alexander.” He runs a hand through Alec’s fringe and Alec leans into the touch, his eyelashes fluttering. “If you let me decide we’ll be here all night and neither of us will be able to walk in the morning.”

Alec’s eyes slip fully closed and he groans low in his throat.

“If we’re still pretending you’re going to get married, it won’t do for you to be completely inexperienced on your wedding night,” Magnus suggests, laughter seeping into his voice. “I think I want to ride you, right here on this couch. For the common good, of course.”

“Oh my god.” Alec manages to laugh and moan at the same time.

The laughter disappears when Magnus leans down to suck another mark higher on his throat. It’s a quick one, because Magnus has better things to do with his mouth; he tongues at Alec’s earlobe and whispers, “Would you like that? I’ve wanted this-“ he rolls his hips pointedly- “inside me since I first saw you.”

_“Magnus.”_

“It’s true,” Magnus purrs, pulling back. “Warlocks can’t lie.”

Alec cracks one eye open. “Yes they can.”

“Yes they can,” Magnus agrees. “But I’m not. Of course, there are plenty of other things we can do. We can simply continue kissing until we both finish in our pants.”

Alec wrinkles his nose. “That’s a thing? People do that?”

“All the time,” says Magnus. “Both of us were well on our way to doing that not thirty seconds ago.”

“I’m not sure I – I think I want to do the… first thing you said,” Alec whispers, blush spreading down his neck and disappearing under his shirt.

Magnus grins, entire body quivering in anticipation. “Hmm, the first thing I said? And what was that?”

Alec hides his face in Magnus’ shoulder, breath hot against his skin. “Don’t make me say it.”

“But you’re so cute when you’re embarrassed,” Magnus laughs, arching his neck to the side as Alec starts to tentatively tongue at his skin, trying to copy what Magnus was doing earlier. “You want to fuck me?”

Alec moans and nods, kissing up the side of his neck and hugging him close.

Magnus shivers. “Say it.”

“Magnus…” Alec whines. Magnus tugs on his hair again and feels the younger man gasp against his throat. “I want to – _oh,_ I want to fuck you, please…”

“So polite,” Magnus murmurs, trying to use humor to cover up the fact that every single little thing Alec’s doing is driving him wild. He pulls Alec’s head back up and kisses him again, letting his hands wander lower and tease at the hem of his black t-shirt.

It feels so natural, so _perfect_ to be kissing Alec like this that Magnus can barely remember how they existed in the same space before this without being attached at the lips. He hisses and digs his fingernails into Alec’s hips when the younger man sucks on his tongue before pressing his own into his mouth.

Magnus is starting to get very, _very_ overheated in his relatively drab suit, so he abandons slipping Alec’s shirt up his stomach in favor of working at the buttons of his own jacket. Alec’s lips slide against his own, their kiss getting sloppy as they both work to get Magnus’ jacket off. Magnus supposes he could just use magic, but that would mean denying Alec the very real pleasure of undressing someone else.

He may or may not have a mental checklist he’s using for Alec’s firsts tonight. None of the many gods who may or may not be watching them are allowed to judge him.

Once they get Magnus’ jacket off, Alec’s fingers immediately fly to the buttons on his dress shirt, nimble and dexterous once he gets the hang of undoing someone else’s buttons. Magnus smiles against his mouth, nipping at his top lip before licking back inside.

When Alec gets his shirt open, Magnus finally goes back to tackling his goal of getting Alec’s shirt over his head. He shoves the hem up over the delicious abs he’d seen several days earlier, then up over pecs that he can’t wait to be acquainted with at close range.

“Alex – ander,” he gets out between kisses. “Help me get this off.”

They break apart for a few seconds to get their respective tops off, and Magnus allows his greedy eyes to take in Alec’s bare chest, the light smattering of hair all over his pecs, muted pink nipples perking up at being exposed.

“You are _exquisite.”_

Alec squirms a little, making like he wants to cover himself up, but Magnus catches his arms and places them back on his waist, warm and comforting. He’s quite proud of his own body, even though Alec’s is definitely more built, and he shivers pleasantly as he watches Alec’s eyes rake down his torso.

A few seconds later they’re back to kissing and it’s getting rougher, sloppier, as Magnus’ fingers trail over the planes of Alec’s abs. Alec’s hands are sliding up and down Magnus’ bare back and it’s so fucking intimate Magnus is almost taken aback. Almost. Mostly he’s just pleased, and so hard it hurts.

Alec makes a desperate, low noise when Magnus’ fingers find his nipples, just teasing for the first few seconds before he pinches lightly and Alec’s back arches up off the couch. Magnus grins and does it again, rubbing his thumbs in circles that make the younger man squirm against him.

He wonders if Alec’s ever done this to himself, but from the way Alec’s reacting, this might be completely new for him.

“Oh, you love it,” he murmurs in wonder.

“Stop talking like that,” Alec chokes out, breath stuttering against his chin when he tries to hide his face. “Magnus, _oh…”_

“Are you _sure_ you don’t want to come just like this?” Magnus teases him, rolling his nipples in between nimble fingers.

Alec shakes his head, stealing another kiss before dragging his lips down over Magnus’ jawline. “Extremely sure. I’ve – I’ve wanted this for a while, I’ve imagined this so many times-“

“Could’ve fooled me,” Magnus snorts, pinching his nipples in retaliation.

“I know, I know, I’m sorry,” Alec mumbles, voice and eyes so broken-open and honest that Magnus drops the teasing immediately. Alec wraps both hands around his neck and pulls him into another kiss, this one mostly lips and teeth as they cling to each other desperately.

“It’s okay, it’s okay, come here,” Magnus keeps murmuring, trying to chase the temporary pain away with lips and hands as they move together sweetly.

He’s getting so into it that his magic’s starting to slip out from under his tight control, prickling goosebumps up and down his arms and shooting out from his fingertips in harmless blue sparks. One second he’s imagining both of them with their pants off and the next they’re pressed up against each other with only underwear separating them – Alec gasps at the sudden heat.

“Shit, sorry, sorry,” says Magnus quickly. “I didn’t – I lost control.”

Once Alec’s gotten over the initial shock, his mouth curves up into a smirk, which looks _devastating_ on his handsome face. “You’re saying _I_ just made a centuries-old warlock lose control? That’s kind of flattering.”

“Yeah, it’s meant to be,” Magnus mutters. “Don’t let it go to your head.”

Alec grins, and Magnus messes up his hair in retaliation. He’s just glad that Alec isn’t freaking out about it, because kissing a guy is one thing but having a nearly-naked guy in your lap tends to make some men who are new to the genre panic. Alec seems more in his element than ever, though, and Magnus smugly wonders how many times he’s imagined this.

Lips trail across his collarbone and Magnus moans, threading a hand tightly in Alec’s hair and scratching down his back with the other one. He rocks forward, blood humming at the contact, and Alec whimpers, mouth open in bliss against his skin. Magnus grins and sends a gentle pulse of magic down Alec’s spine, nothing huge, just a little rush of endorphins, but Alec reacts to it like Magnus used his full power, crying out sharply as his cock twitches in his boxer briefs.

“I’d better get on you before you end this too soon, Alexander,” Magnus smiles.

Still shuddering, Alec leans back up to glare at him. “We should be _fine_ as long as you don’t do _that_ again.”

“Mmm.” Magnus leans forward to nip at his earlobe again, then presses his tongue sharply against one of the bruises he’s already left. “You may be underestimating how tight I’ll be.”

 _“And_ as long as you stop talking,” Alec adds quickly. His hands wander down to squeeze at Magnus’ ass, and it feels so good that Magnus purrs against his throat.

There’s definitely a growing wet spot on the front of Magnus’ briefs – thank god he had thought to wear underwear to the trial, as he normally goes without and _that_ would have been a shock all at once for Alec – but Alec isn’t much better, rutting up against him with growing confidence and groping Magnus’ ass like he’s physically incapable of letting go.

When Alec kisses him this time there’s a growing hunger behind it, and as he gains more confidence he starts to fuck his tongue in and out like that’s what he’d do to Magnus’ ass if given the chance. That thought – and the realization that he _himself_ is going to end this too early if they don’t get down to it – is what spurs Magnus into action.

He pries Alec’s hands off him but only so he can slide the waistband of his briefs down, down until it’s resting below his cheeks; Alec’s breath hitches against his mouth before his hands start to wander again, grabbing at exposed skin and mapping out new territory.

“You’re welcome to take them all the way off,” Magnus whispers against his mouth.

Alec looks a little stunned, like he forgot that having penetrative sex would involve them taking _all_ of their clothing off, and he bites his own lip before looking down between them and slowly sliding Magnus’ waistband even further down.

Magnus arches his back languidly, unashamedly vain, before he realizes that Alec can’t make much progress with the way Magnus’ thighs are spread over his lap. A snap of his fingers solves that problem, and Alec gasps.

“Sorry, I _really_ didn’t want to get up,” Magnus drawls. Alec’s mesmerized by the bob of his cock; Magnus leans down to press kiss after fond kiss to his slack lips.

“You’re so hot,” Alec eventually gets out, rubbing over his bare thighs with shaky fingers.

“As are you,” says Magnus.

Alec blushes. “You haven’t even seen all of me.”

“I don’t have to, to know you’re attractive,” Magnus grins. “Now, should I get up, or…?”

“Oh,” Alec says, eyes wide. His grip on Magnus’ thighs tightens. “No, you can… um… that thing you did…”

Magnus hums. “As you wish.” He snaps his fingers again, willing Alec’s boxer briefs to the pile of clothes on the floor, and shudders at the throb of heat in his belly when he sees Alec’s perfect body, completely bare. “Oh, Alex _ander.”_

Alec squeaks when Magnus kisses him again, even rougher this time, and Magnus cups his face tenderly and tries to convey all of his emotions through his trembling hands. When their bare cocks press together for the first time Magnus loses control of his powers again, sending a wave of heat through his hands that makes Alec’s eyes roll back in his head while simultaneously willing a large quantity of lube from his bedroom to slick up his ass. At least when Magnus loses control it’s productive.

Once Alec can focus again Magnus wraps a hand around him for the first time and he swears quietly, glancing in between them – Magnus swipes a thumb over the head of his cock and watches gleefully as precome beads out, all for him.

“Magnus-“

“Shh, I’m done teasing, I promise,” Magnus tells him, kissing his forehead as he kneels up in giddy preparation to sit on his cock.

Alec stops him, though, with a tight grip of legs. “Wait.”

Dread roars through him and he feels like he’s just been doused in cold water. If Alec’s having second thoughts – has he been worried this whole time, has Magnus even asked for _consent-_

“I thought you needed to, um, get ready first,” is what comes out of Alec’s mouth.

Magnus exhales, unsure if he’s ever felt more relieved. “You’re sure you want to do this?” he asks, just in case.

“Yes,” Alec says immediately. “Yes yes yes.”

“Well, that’s good,” Magnus smiles. “And I’ve already done some of the preparation using magic.”

“Some?”

Now it’s Magnus’ turn to blush, but only slightly. “I’ve found that I enjoy the… burn that comes from not being fully prepared. But you’re welcome to do a thorough job, if you’d like.”

Alec looks up at him reverently, almost shyly. “I wouldn’t – I don’t know what to do.”

“It’s pretty simple, see?” Magnus makes a crude gesture with his fingers that has Alec slapping them away in embarrassment. “Just do one at a time, sweetheart.”

Magnus spreads his legs a little further so Alec doesn’t have to blindly feel around too much (not that he’d mind at all, it’s just that he has a much _more_ pleasurable endgame in mind), and Alec pushes one finger tentatively against him and gasps when he feels the slick. Magnus hisses as he presses inside – his hands are very large and his _fingers_ are something else and _gods_ he can’t wait to sit on top of him.

“Does that feel okay?” Alec asks, his face very serious.

Magnus grins and cups his face, kissing him gently. “It feels wonderful.”

Alec looks encouraged by this and he adds another, clumsily fucking them in and out a few times before he gets a rhythm going. Magnus arches back into it and groans happily when Alec’s fingertips brush against his prostate. “Right there, again – _yes.”_

Alec looks _very_ encouraged now; Magnus watches him through half-lidded eyes as he bites his lip and really goes after it. There’s a fire burning in his tummy and every stroke of Alec’s fingers is just fanning the flames. Fuck, but he’s so _beautiful._ He’s earnest in his concentration as he adds a third finger, wedging them inside as Magnus rolls his hips and moans at the stretch.

“Yeah?” Alec asks, eyes so intense Magnus could drown in them.

“Yes, I’m – I’m ready,” Magnus half-whines. _“Please,_ Alexander, I need you.”

Alec licks his lips and kisses him again, fingers still buried inside him. Magnus reaches for his cock again and strokes him up and down a few times, feeling slightly chaotic and urgent as he starts to bounce on Alec’s fingers.

“Oh fuck,” Alec groans, “Mag – _Magnus,_ okay, come on-“

Magnus laughs against his lips and raises up on his knees once more, cleaning Alec’s fingers with a flick of his wrist as he lines himself up. There’s a moment, then, their faces so close they’re breathing each other’s air – Alec’s eyes are so _gorgeous_ and Magnus is so _happy_ he could cry – and then they’re kissing again, slowly, like they have all the time in the world.

Like Magnus isn’t hovering over Alec’s cock and straining not to just sit the fuck down on it.

Instead, he lowers himself slowly, shuddering happily when he feels the thick head press up against him. Alec’s eyes flutter closed and he sinks his teeth harshly into his bottom lip so hard it turns white. Magnus grins and lowers himself an inch further, moaning happily because – _fuck,_ because even the prep of three fingers couldn’t quite accommodate for the size of Alec’s cock. It burns a little bit, and it’s fucking _delicious_.

Once the head is inside, Alec’s eyes pop open, lip still trapped between his teeth. He looks wild, the brown of his irises now completely swallowed up by his pupils, and he’s rubbing up and down Magnus’ thighs mindlessly like it’s grounding him.

“Magnus, I, oh – _oh-”_ he groans, eyelashes fluttering as Magnus takes more in. “Oh gods-”

“Oh, you’re _perfect,”_ Magnus purrs, gritting his teeth against the stretch and relishing the burn. “How are you feeling?”

Alec opens his mouth like he’s going to say something, but Magnus keeps moving down and he stutters out a low groan instead – he tips his head back and breathes raggedly, dark hair fanned out against the back of the couch. Magnus is being selfish, he knows, doesn’t want to stop until he’s taken all of him, and he lets out his own satisfied groan when he sits all the way down.

“Don’tmovedon’tmovedon’tmove,” Alec stammers, staring up at the ceiling with wide eyes. His hands are shaking. “I’m so – I’m going to – please just stay still-”

Magnus’ abdomen twists with hunger. Virgin Shadowhunter energy, no more. “Of course.”

“Jace told me about a – stamina rune once,” Alec babbles, still breathing fast. “If I’d been – paying more attention I could, _nnh,_ could maybe remember it-”

“You don’t need a stamina rune for your first time,” Magnus tells him kindly. He’s trying very hard not to clench around him, but every little thing Alec’s doing is making his insides flutter. “Your first time should be organic. _Well,_ as organic as sex with a warlock can be.”

The air around them crackles pointedly and Alec moans, finally looking at Magnus again. “Is there anything – you can do to – take the edge off?”

Magnus grins. “Yes. But perhaps I like seeing you this desperate.”

 _“Magnus.”_ Alec looks angry but there’s no heat behind it – at least, not _that_ kind of heat. His brows are drawn together and a bead of sweat is trailing down the side of his neck.

“Alright, alright.” Magnus hasn’t done sex magic in a while and he’s loathe to shake off the cobwebs and try anything while Alec is literally inside him, so he settles on a more multipurpose spell that will distract Alec’s brain just enough to make him forget that he’s losing his virginity and was never expected to last more than a minute.

When Alec’s eyes clear from the fog of the spell, he looks much more relaxed, and his hands move with more confidence the next time they slide up Magnus’ thighs. “Thanks.”

“Alexander, I just saved you from the embarrassing first-time story that almost everyone has universally had to endure,” Magnus tells him, stroking a thumb over one of the dark bruises on his neck. “You owe me a very large favor.”

He rocks up and down, once, a small movement, to give Alec an idea of exactly what _large_ favor he has in mind. The slick drag inside him feels incredible and Alec’s eyes go wide, his chest heaving when Magnus does it again.

“Mmmm,” Magnus sighs, bliss crawling through him. He drags a hand down Alec’s chest appreciatively as he starts to actually ride him oh-so-slowly.

Alec looks like he’s having a religious experience, mouth slack, lips swollen from their frantic kissing. Magnus has never seen him more open and trusting and it makes his heart ache – he threads both hands in Alec’s soft hair and drags their mouths close, then brushes his lips gently over Alec’s as they move together.

“Oh fuck, oh, _fuck,”_ Alec groans, his hips chasing Magnus’ every time Magnus moves up, like he wants to stay completely inside. “Magnus, I, _mmnnn-”_

“You feel amazing,” Magnus mumbles against his lips. He pulls back, then, and really starts to move up and down, grinning at the slap of skin on skin that starts up after he’s bounced a few times. Alec’s eyes are huge. “I wasn’t joking when I said I thought about _exactly_ this when I first saw you – _yes –_ how pretty you’d look under me.”

His cock is dragging against Alec’s abs and leaving smears of precome behind, decadent, pleasure racing through him as he tugs Alec’s head back and dives down to suck another bruise onto his neck. Alec whines low in his throat, the sound vibrating under Magnus’ lips, and he wraps his hands around Magnus’ waist and holds on tightly.

If Magnus angles his hips forward just so, it changes the angle so that Alec’s cock drags over his prostate every time he sits down on it. It’s terribly, _terribly_ addicting and Magnus can’t help but move faster; he sucks teasingly on Alec’s earlobe and whispers, “How does it feel?”

Alec just moans, clutching at his hips before dragging his hands down to settle on his ass.

“Tell me,” Magnus insists.

“I can’t,” Alec whispers, his voice breaking. Magnus pulls back to grin at him, working his hips differently so he can keep that delicious angle. “It’s – _ah,_ too much, I _can’t,_ Magnus…”

“Oh, but you’re taking it so well,” Magnus coos, stroking a hand over his face. Hot pressure is starting to twist low in his gut but he pushes it back, determined to make this last longer even though Alec’s cock is sinfully perfect. He’s never going to be able to look at Alec again without remembering this, how wrecked he looks, the desperation in his grip.

The fire crackles behind them as the intensity grows between them; there’s a bit of blood on Alec’s lower lip where he’s been biting it and Magnus leans in to lick it off, making them both moan as he keeps moving fluidly. They’re not kissing so much as panting against each other, really – Alec’s mouth is slack but his hips are starting to really move and he’s _strong,_ thrusting up off the couch in powerful little motions that bounce Magnus on top of him.

Magnus hisses in pleasure and tugs at his hair, biting at his mouth. When Alec pulls back to gasp in air Magnus realizes how _truly_ fucked he looks; his hair’s a mess, his neck is covered in bruises, his lips are swollen and the bottom one’s still fucking bleeding.

 _“Gods,_ that’s it,” Magnus purrs, elated at how thoroughly he’s managed to debauch the younger man. “Fuck me, _yes,_ oh, give it to me-”

Alec makes a broken noise and lunges for his mouth again, and his hips come up off the couch in such a way that his cock presses _hard_ against Magnus’ prostate and makes him see stars. It throws him off enough that when Alec’s too enthusiastic and overbalances them Magnus can’t even stop him, and they both end up tumbling onto the soft, fluffy rug in front of the fireplace.

Magnus laughs, delighted and hungry at the sight of Alec looming over him. “Multiple positions… _ambitious,_ Alexander.”

Alec’s breathing hard. “Sorry, I – I didn’t-”

“Oh, it’s quite alright,” Magnus grins. The firelight is reflecting in Alec’s eyes and illuminating the handsome planes of his face. “Do you want me back on top?”

He rocks his hips a little bit to make his point and Alec’s breath catches. Alec thrusts forward once, tentative, then his eyes light up and he does it again, this time with more force. “Like this is… I wanna try like this.”

The power behind his hips makes Magnus hiss happily next time he buries himself inside – he draws Alec into a bruising kiss until they’re pressed so close together there’s not a bit of space between them. They’re both sweating, from exertion and from the heat of the fire, and as their bodies slide slickly together Magnus sends another small pulse of magic through the younger man to show his appreciation.

“Unnh, oh my – please _please,”_ Alec stammers against him, his hips stuttering as he loses his rhythm.

Magnus grins and strokes over his broad back when Alec tucks his face into Magnus’ shoulder, hiding there shyly even as he fucks him hard. Alec looks gorgeous like this, his pale back muscled and covered in runes, pert little ass flexing every time he drives in. It’s tempting to just let go and fall over the edge but Magnus _needs_ to hold on, needs this to last even longer and ruin him for anyone else because Alec’s already _done_ that to the rest of him.

“That’s it,” he tells Alec, stroking over his hair. Alec sobs into his neck, muffled. “Ohh, you’re _so_ good, darling.”

He wants to wrap his legs around Alec’s waist and keep him close – gods, it feels so full and _fantastic_ when Alec’s all the way inside, but the movement in-and-out is what feels the best.

“Magnus – _Magnus,_ ohhh…”

 _“Yes,_ keep going,” Magnus encourages him. “Can you go harder?”

Alec shakes his head rapidly even as his body listens to what Magnus is telling him. “I can’t, I’m gonna – _nngh,_ I’m so close, _fuck.”_

“So am I,” grins Magnus, digging nails into his back when Alec hits his spot just right. He wants to come seeing Alec’s face, though, so the next time Alec buries himself inside, Magnus gets the leverage to roll them over so he’s back on top. Alec’s breathing hard, chest shining with sweat in the firelight, and he closes his eyes and cries out when Magnus drags his nails down the planes of his abs.

“Are you going to come inside me, Alexander?” Magnus pants, rolling his hips and fucking himself on Alec’s cock.

He’s egging Alec on and it’s so much fun, _so_ much fun to tease him and pinch his sensitive nipples now that he’s hanging on the edge of orgasm. He’s moving too fast to really tell but he’s _pretty_ sure that Alec’s actually twitching inside him every time Magnus plucks at his nipples.

“Magnus, please… _please,”_ Alec groans, his hands wandering up and down Magnus’ body as he rides him in fluid movements.

Something about the way Alec’s eyes are gleaming causes heat to surge through Magnus’ entire being, and he whimpers urgently before grabbing hold of his neglected cock and stroking up and down quickly. Alec swallows and pets at his thighs clumsily, his eyelashes fluttering against his pale skin – Magnus can practically _taste_ how close he is and the thought of Alec coming inside him is going to push him over the fucking _edge._

He wants to memorize everything about this moment, _every little thing,_ and with his free hand Magnus grasps for one of Alec’s, clinging to him as the heatwave inside him starts to crest.

“Ohmygodohmygod,” Alec babbles, his face twisting in pleasure as Magnus starts to spasm around him.

The wave breaks at that, devastating surges that have Magnus crying out and clinging to Alec’s hand as he rocks back and forth. He manages to keep his eyes open, hisses out _“yes”_ when Alec throws his head back and cries out, his hips jerking up helplessly. His back is arched and Magnus is getting come all over his chest and _now_ he closes his eyes, hoping that picture will be seared into his brain forever as he rides out the rest of his orgasm.

Magnus flops onto Alec’s chest when it’s over, looking up at the younger man fondly. Alec’s eyes are closed and he’s still moaning a little bit every time he breathes out. Magnus mentally pats himself on the back.

He knows this temporary peace won’t last, and that the world is still turning outside his apartment, but right now Magnus can’t be fucked to care about anything but the boy underneath him. Alec makes a small noise and wraps his arms around him, and Magnus smiles, knowing that whatever comes tomorrow, or the next day, or the next, they’ll always have this night.

This _whole_ night.

Magnus is already planning round two when Alec finally recovers enough to kiss him on the forehead. Oh, this is going to be _fun._

**Author's Note:**

> Let me know what you thought in the comments or on tumblr, if you'd like! :)

**Works inspired by this one:**

  * [Thunder's Getting Louder](https://archiveofourown.org/works/6411718) by [Teumessian](https://archiveofourown.org/users/Teumessian/pseuds/Teumessian)




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